We propose the rise of crack cocaine markets as an explanation for the end to the convergence in black-white educational outcomes beginning in the mid-1980s. After constructing a measure to date the arrival of crack markets in cities and states, we show large increases in murder and incarceration rates after these dates. Black high school graduation rates also decline, and we estimate that crack markets accounts for between 40 and 73 percent of the fall in black male high school graduation rates. We argue that the primary mechanism is reduced educational investments in response to decreased returns to schooling.

How did crack cocaine depress schooling returns? "Crack markets had three primary impacts on young black males: an increased probability of being murdered, an increased risk of incarceration, and a potential source of income," explain the authors. "Each limits the benefits of education." In other words, high school looks less attractive when you're more likely to end up dead or in jail, or earn money.

The AP reports that Brazilian drug lords are colluding to get rid of crack cocaine even though it will result in millions of lost dollars. Why? Because crack customers have made their jobs unmanageable:

"Rio was always cocaine and marijuana," [former police chief Mario Sergio Duarte] said. "If drug traffickers are coming up with this strategy of going back to cocaine and marijuana, it's not because they suddenly developed an awareness, or because they want to be charitable and help the addicts. It's just that crack brings them too much trouble to be worth it."

A new study by addiction and neuroscience researchers sheds new light on understanding how cocaine addicts make decisions, and how they value the drug against the immediate and delayed reward of other items, such as cash. The upshot is that addicts discount cocaine at a steeper rate than they do money, consistently choosing to have money now, rather than twice the value of cocaine later. Here's how the experiment worked:

Forty-seven cocaine addicts (who were all seeking treatment) were asked to guess the number of grams of cocaine worth $1,000. They were each then given a series of choices: cocaine now versus more cocaine later; money now versus more money later; cocaine now versus money later; or money now versus cocaine later. The initial amount offered for the immediate choice has half of the full value, and the delayed amount was always the full value. Preference was almost exclusively given to the money now option, according to the study's lead researcher, Warren K. Bickel, a psychology professor at Virginia Tech, and director of the Advanced Recovery Research Center there.

Last week was the sixth annual Operation Rolling Thunder police crack-down in Spartanburg, SC. Each year, law enforcement from North and South Carolina converge on the Spartanburg interstate highways for a five-day dragnet aimed at drug trafficking. This year officers made 18 felony arrests, netting $215,000 of seized cash, 11 pounds of cocaine, and eight pounds of marijuana.

"The numbers are a bit lower than in the past, I'm proud of that, meaning they are staying out of Spartanburg County, which that is our desire,” said Sheriff [Chuck]Wright. “I try to tell everybody that every piece of drug paraphernalia or drug you can find and get off the street, that's one more somebody's son or daughter that's not having to deal with that.

Researchers examined data on more than 44,000 drivers in single-vehicle crashes who died between 1999 and 2009. They found that 24.9% tested positive for drugs and 37% had blood-alcohol levels in excess of 0.08, the legal limit. Fifty-eight percent had no alcohol in their systems; 5% had less than 0.08. The data were from a government database on traffic fatalities.